In many cases, custom-moulded ear-plug devices must be customized in adaptation to the particular area of application. This is especially true for in-ear custom-moulded ear-plug devices which must be specially adapted to the shape of the ear canal of the individual concernedxe2x80x94a typical requirement most of all for in-ear hearing aids. But for other in-ear custom-moulded ear-plug units as well, such as earphones and protective noise- or water-blocking ear plugs, this is highly desirable for optimal wearing comfort. Even for outer-ear custom-moulded ear-plugs it would often be desirable to enhance the wearing comfort by custom-fitting the custom-moulded ear-plug device. It is primarily in the fabrication of such custom-moulded ear-plug devices, especially when they have to be equipped with correspondingly customized modules such as electronic components, that problems are encountered in terms of reliable contour duplication and the avoidance of mix-ups first of the custom-moulded ear-plug shells and then of the modules to be installed in them, problems which can be solved only at relatively great expense. But problems arise even in the case of custom-moulded ear-plugs which are produced without incorporating customized modules such as the aforementioned electronic components, by virtue of the fact that, after all, one has to make certain that the correct individual custom-moulded ear-plug device is shipped to the right recipient.
It is the objective of this invention to provide an custom-moulded ear-plug device which will solve these problems in extremely simple fashion. To that end, the shell of the custom-moulded ear-plug unit according to this invention is provided with molded-in projections or indentations for marking purposes.
According to this invention, the novel process that solves the problem referred to above is characterized in that a shell of the custom-moulded ear-plug device is produced with individually identifying markings, the individualized shell serving to identify the product. By means of that individualized shell which accompanies the job, any further product completion such as, in particular, the assembly of the shell with the modules to be built-in such as electronic components, batteries etc., can be customized. At least the shell will allow at any time the identification of a specific job so that even in a manual fabrication i.e. assembly process the installation of the correct modules can be assured. In a particularly preferred implementation of the process per this invention which makes optimal use of the novel, individualized marking method, at least some of the subsequent production steps following the fabrication of the shell are automated with the aid of machine recognition of the markings. The process per this invention is especially suitable for the fabrication of in-ear or outer-ear hearing aids, and particularly so for in-ear hearing aids which require an extra measure of attention to individualized production details and the avoidance of any mix-ups, given the considerable differences in the shape of each person""s auditory canal. Custom-moulded ear-plug devices eligible for the implementation of this invention, and preferred design versions thereof, are described below with reference to the drawings in which, by way of example: